Railway signaling apparatus



2 Sheets-Sheet 2 Filed April 6, 1969 Rail factor [Station Plazffioz'm 1 10 INVENTOR. George E E'llard BY A). L W

HIS ATTORNEY:

United i atent @ffiee 3,654,889 Patented Sept. 18, 1962 3,054,389 RAKLWAY SHCNAHNG AlPfARA'lUS George E. Ellard, Lexington, Mass, assignor to Westinghouse Air Brake Company, Wilmerding, Pan, a corpora= tion of Pennsylvania Fited Apr. 6, 196% Ser. No. 29,351 Claims. (Cl. 246-33) My invention relates to railway signaling apparatus, and particularly to apparatus, in a railway block signaling system, for permitting a following train to at times enter a signal block at an earlier time than usually per-- mitted after the departure of a preceding train from the block.

In railway block signaling systems for stretches of railway track over which trains travel in a single direction and at times with close headway such, for example, as in signaling systems for subways when trains are operating during the rush hours, it is desirable, in order to expedite the rush-hour crowds, to obtain the closest possible spacing of the trains commensurate with safety. In railway station platform areas, since a preceding train departing from the station platform is accelerating and a following train approaching the platform is decelerating to come to a stop at the station, it is particularly true that closely following trains may be unnecessarily distantly spaced. In systems heretofore devised for permitting closer headway of trains under such conditions, a succession of signals are located in the approach to a station platform and, if a first train is at the platform or departing therefrom each signal is permitted to advance to a less restrictive indication only if the speed of a second train approaching the station is at or below a predetermined maximum speed as it approaches the signal. Such closing-in signal control arrangements, as they are usually termed, are well known in the art and are usually relatively expensive due to the large number of signals and track circuits required.

It is accordingly an object of my invention to provide an economical arrangement for closing-in signal control to at times provide closer headway of trains in an automatic block signaling system.

It is another object of my invention to provide apparatus and circuitry to obtain, in accordance with a new concept of closing-in signaling, closer spacing of trains at certain locations in an automatic block signaling system.

Other objects and characteristic features of my invention will become apparent as the description proceeds.

While I have referred to my invention as being especially useful in subway signaling systems and have illustrated my invention in the accompanying drawings in conjunction with a stretch of railway track in a station platform area, it will be understood that my invention is not limited to such uses, but that it may be employed at any location in an automatic block signaling system where it is desired to permit a following train to close in on a preceding train without the loss of the usual safety provided by the signaling system.

In accomplishing the foregoing objects of my invention I provide timing means in one block of an automatic block signaling system to determine whether a train occupying that block is traveling at or above a predetermined speed and, if such is determined to be the case, additional means are operated to control the signal governing the entrance of trains into the block next in the rear to permit a following train to enter that block at an earlier time than usually permitted.

I shall describe three forms of apparatus embodying, my invention, and shall then point out the novel features thereof in claims.

In the drawings,

FIG. 1 comprises a schematic wiring diagram illustrating one form of my invention employed in conjunction with a typical automatic block signal system for a stretch of railway track illustrated in the upper portion of the figure.

FIG. 2 shows a schematic wiring diagram illustrating a second form of my invention utilized in conjunction with a signaling system for the stretch of track shown in FIG. 1.

FIG. 3 comprises a schematic wiring diagram showing a third form of my invention used in conjunction with an automatic block signaling system for the stretch of railway shown at the upper portion of the figure. The stretch of railway track shown in FIG. 3 is similar to that of FIG. 1 but is divided into track sections in a different manner from that of FIG. 1, as will be described.

Similar reference characters refer to similar parts in each of the figures.

Referring first to FIG. 1 the reference characters 10 and 11 designate the rails of a stretch of railway track over which trains normally move in the direction indicated by the arrow. These rails are divided by insulated joints I into a first track section or signal block designated 1T, adjacent a station platform, and a second signal block or track section beyond said platform in said direction of travel and designated 2T. Each section is provided with a track circuit including a track battery, designated B, connected across the rails at one end of the section, and a normally energized track relay, designated R, connected across the rails at the other end of the section, each said designation having a prefix the same as the reference character for the associated signal block or section.

A first wayside signal 16 is located at the entrance end of signal block or track section IT for governing the movements of trains into that block, and a second signal 25 is located at the entrance end of signal block 2T for governing the entrance of trains into that block. A third signal 3G illustrated by dotted lines is located at the exit end of block 2T. This latter signal comprises an entrance signal for the next successive signal block, but since its controls form no part of my present invention, no means are shown for controlling it. Signals 1G and 2G may be of any of the well known types of railway signals but are here shown as being of the color light type having only a stop lamp R and a proceed lamp G. In actual practice the signals may be provided with other lamps for giving additional indications.

There is also located in signal block 2T a timing section, the limits of which are determined by the circuit controllers CA and CB. While these circuit controllers are shown in the drawing as being rail contactors it will be understood that any device which will detect the passage of the front end of a train can be used for the controllers CA and CB. That is, these devices may take the form of pedal devices, wheel actuated treadles, etc., the use and operation of such circuit controlling devices being well known in the art. Controller CA is preferably located a sufficient distance within signal block 2T that signal block 1T will be vacated before the front end of the longest train to travel the track stretch reaches the controller. Controller CB is located a predetermined distance beyond controller CA so that the speed of a train traversing signal block 2T may be determined by the time interval between actuation of controllers CA and CB. For example, the controllers may be located 33 feet apart and, if the train traversing the section actuates both controllers in 0.75 second or less, the train will be known to be traveling at a speed of 30 mph. or greater when traversing the timing section between controllers CA and C13. The purpose of this example will be set forth later in this description.

Circuit controller CA is provided with a normally open movable contact a and normally closed movable contact b shown directly beneath the controller and indicated as controlled thereby by the dotted line extending from the controller to the contacts in the usual manner. Circuit controller CB is provided with a normally open contact a shown directly beneath that controller in a manner similar to the contacts of controller CA. These normally open and closed contacts are actuated to closed and open positions respectively when their associated controllers are operated or actuated by the passage of a train in the manner well known in the art. Circuit controller CA must be Provided with a buffer mechanism so that the con troller will be of a slow-return type. That is, when contacts a and b of the controller are actuated to closed and open positions respectively by the passage of t e front end of a train they must maintain such positions during the passage of the entire train. This may be accomplished by using for controller CA a track instrument, pedal, or treadle provided with buffer means which are also well known in the art and may, for example, be similar to that shown and described in Letters Patent of the United States Serial No. 2,588,798 issued November 27, 1948, to H. L. Bone et al. for Buffer Means. The purpose of employing a slow-return type of rail contactor for controller CA will become apparent as the description proceeds.

There is also shown in FIG. 1 a slow release or timing relay TER and a repeater or stick relay TESR. The slow release feature of relay TER is indicated in the usual manner by an arrow pointed downward through the movable portion of the contact of the relay and the purpose of this feature Will be set forth hereinafter.

It should be pointed out at this time that a suitable source of control current is provided for each of the forms of apparatus of my invention shown in FIGS. 1, 2 and 3; this current source being preferably a battery of proper voltage and capacity. However, for the sake of simplicity this current source is not shown in the drawings but its positive and negative terminals are identified in each figure by conventional reference characters B and N, res ectively.

Referring further to FIG. 1, relay TER has a pickup circuit extending from terminal B of the battery, over contact b of controller CA, and through the winding of the relay to terminal N of the battery. Thus, relay TER is normally in a picked-up position.

Relay TESR is provided with a pickup circuit extending from battery terminal B, over contact a of controller CB, contact a of controller CA, front contact a of relay TER, and through the winding of relay TESR to terminal N of the battery. Relay TESR is provided with a stick circuit extending from battery terminal B, over back contact of track relay ZTR, front contact a of relay TESR, and through the winding of relay TESR to terminal N of the battery. Relay TESR is, therefore, picked up when controllers CA and CB are both actuated to close their contacts a and relay TER is in its picked-up position, and is maintained picked up when once picked up, so long as signal block 2T is occupied by a train as reflected by the released position of track relay ZTR and the consequential closing of back contact 0 of that track relay.

Each of the signal lamps R and G of signal 16 has multiple energizing circuits. The first energizing circuit for lamp R extends from battery terminal B, over front point of contact b of relay ZTR, the back point of contact a of relay 1TR, and through the filament of the lamp to battery terminal N. The second energizing circuit for lamp R extends from battery terminal B, over the back point of contact b of relay 2TR, the back point of contact b of relay TESR, and the filament of the lamp to battery terminal N. The first energizing circuit for lamp G of signal 1G extends from battery terminal B, over the front point of contact b of'relay ZTR, the front point of contact a of relay lTR, and the filament of the lamp to battery terminal N. The second energizing circuit for lamp G extends from battery terminal B, over the back point of contact b of relay ZTR, the front point of contact b of relay TESR, the front point of contact a of relay lTR, and the filament of the lamp to battery terminal N. Thus signal 16 is controlled to give a proceed indication only when signal blocks IT and 2T are both unoccupied; or when block IT is unoccupied, block 2T is occupied, and relay TESR is in its picked-up position, as hereinafter described.

Signal lamp G of signal 26 has an energizing circuit extending from terminal B of the battery, over the front point of contact a of relay ZTR, and the filament of the lamp to battery terminal N. Signal lamp R of signal 2G has an energizing circuit extending from terminal B of the battery, over the back point of contact a of relay ZTR, and the filament of the lamp to battery terminal N. Thus, signal 26 is controlled to give its stop or proceed indications accordingly as signal block 2T is occupied or unoccupied by a train.

I will now describe the operation of the form of my invention shown in FIG. 1 when a train enters signal block ET and then, after a stop at the station platform, leaves the station and proceeds through signal block 2T at a speed above a predetermined speed. When the apparatus of FIG. 1 is in its normal condition as shown in the drawing, relay TER is energized, relay TESR is deenergized, both track relays are energized, circuit controllers CA and CB are in their unactuated positions, as shown, and signals 1G and 2G are both giving their proceed indications. A train approaching the station platform area accepts the proceed indication of signal 16 and enters signal block 1T. Relay HR is thereby released controlling signal 16 to change its indication fro-m proceed to stop by closing the first previously described energizing circuit for lamp R of signal 1G at the back point of contact a of relay lTR. No other operation of the apparatus takes place at this time.

After the train has stopped at the station platform, it accepts the proceed indication of signal 2G and enters into and proceeds through signal block 2T at an accelerating speed. The entrance of the train into signal block 2T releases track relay ZTR and changes the indication of signal 2G from proceed to stop. The release of track relay 2TR also changes the circuit for energizing lamp R of signal 1G from the first energizing circuit for that lamp to the second energizing circuit including the back point of contact b of relay ZTR. When the train vacates signal block 1T, track relay lTR again picks up closing the front point of its contact a, but signal 1G continues to give its stop indication, the second energizing circuit for lamp R of that signal remaining closed at the back point of contact b of relay ZTR.

I will now assume, for an example, that it has been determined that if the speed of a train when passing through the timing section, represented by the distance between circuit controllers CA and CB, is 30 mph. or greater, the train has sufficient inertia that a second or following train could be safely permitted to enter signal block IT to make a stop at the station platform. That is to say, at 30 mph. the distance that would be required for the first train to come to a stop is sufficiently great that the second train can be permitted to enter signal block 1T without the requirement of the usual safety overlap provided by signal block 2T. In the example previously described it was set forth that controllers CA and CB are assumed to be located at points 33 feet apart and it would require a train traveling at 30 mph. 0.75 second to traverse the timing section. It is therefore apparent that signal 1G may be permitted, in the examples, to give its proceed indication while a train occupies signal block 2G, provided the train traverses the timing section in 0.75 second or less. Accordingly for purposes of this example relay TER is so selected that its slow release feature provides a delay time of 0.75 second for release of the relay armature after the deenergization of the winding of the relay. It is readily apparent that the speed required for a train to have attained, when traversing the timing section, may be greater or less than 30 m.p.h., and in each case the length of the timing section may be changed to correspond with the changed required speed, the slow release time delay of relay TER may be changed to suit the varied conditions, or both changes may be made to a suitable degree.

When the train traversing signal block 2T actuates circuit controller or contactor CA, contact b of that device is actuated to an open position and opens the previously described pickup circuit for relay TER; Relay TER being slow release, however, front contact a of the relay will not open until the expiration of 0.75 second. If the speed of the train is under 30' mph, the time delay period of 0.75 will expire and relay TER will release opening its front contact a before contact a of circuit controller CB will be actuated to its closed position. Thus, the pickup circuit for relay TESR will not be completed and no further action will take place until the train vacates signal block 2T. However, if the speed of the train is 30 mph. or greater, circuit controller CB will be actuated to close its contact a prior to the opening of front contact a of relay TER, and the previously described pickup circuit for relay TESR will be completed. When relay TESR picks up it completes its stick circuit including its own front contact a and back contact 0 of track relay ZTR.

Relay TESR, being thus controlled to its picked-up position, opens the previously described second energizing circuit or lamp R of signal 1G and closes the previously described second energizing circuit for lamp G of signal 1G including the front point of contact b of relay TESR. Signal 16 now gives its proceed indication to permit a second train to enter signal block 1T.

When the train traversing signal block 2T vacates that block, relay ZTR will pick up, open the stick circuit for relay TESR to cause release of that relay and transfer the energization of the lamps of signal 2G from the stop lamp R to the proceed lamp G. Signal 1G will con tinue to give its proceed indication since its control circuits are merely transferred from the previously described second energizing circuit for lamp G of that signal to the previously described first energizing circuit of that lamp. The apparatus shown in FIG. 1 has now returned to its normal condition.

Referring now to FIG. 2, there is shown a second form of my invention for use in the track layout and the signal arrangement shown in FIG. 1. The circuits for energizing the lamps of signals 16 and 2G are not shown as extending to the lamps of the signals shown in FIG. 1 but the lamps of signals 1G and 26 are shown in FIG. 2 in dotted rectangles with designations to identify each respective signal. It will be readily understood that the signal lamps shown in FIG. 2 represent the lamps of signals 1G and 2G appearing in FIG. 1. It will also be understood that the track relay and circuit controller contacts shown in FIG. 2 represent contacts on the track relays and controllers appearing in FIG. 1.

In the apparatus arrangement of FIG. 2 circuit controller CA may, but need not be, a slow-return-tomormalor buffered controller as in the form of my invention shown in FIG. 1 and previously explained. The reason the controller need not be a buffered type will become apparent as the description proceeds.

The scheme of FIG. 2 operates in a manner similar to that of FIG. 1 but incorporates checking features to be described, and employs two additional relays ASR and HR. Relay ASR has a pickup circuit which extends from battery terminal B, the front point of contact 0 of track relay 2TR, and the winding of relay ASR to battery terminal N. Relay ASR has a stick circuit which may be traced from battery terminal B, con-tact b of circuit controller CA, closed in the unactuated condition of the controller, front contact a of relay ASR, and the winding of relay ASR to battery terminal N. Thus, relay ASR is normally held in its picked-up position by its pickup circuit and also by its stick circuit.

Relay TER in FIG. 2 has a pickup circuit extending from battery terminal B, over front contact b of track relay ITR, front contact c of relay ASR, and the winding of relay TER to terminal N of the battery. Thus, relay TER is in its picked-up position so long as signal block IT is unoccupied and relay ASR is in its pickedup position.

Relay TESR in FIG. 2 is provided with a stick circuit identical to the stick circuit for relay TESR in FIG. 1; and has a pickup circuit which may be traced from terminal B of the battery, over contact a of controller CB, closed only when the controller is actuated, front contact a of relay TER, back contact b of relay ASR, and the winding of relay TESR to battery terminal N. The operation of relay TESR will be described hereinafter.

The signal control circuits for energizing lamps G and R of signal 16 are identical to those shown in FIG. 1 and no detailed tracing of these circuits is necessary. In the signal control circuits for signal 2G of FIG. 2 a signal control relay previously mentioned and designated HR is employed. Relay HR has a pickup circuit extending from terminal B of the battery, over contact b of controller CB, closed in the unactuated condition of the controller, contact a of controller CA, closed in the unactuated condition of the controller, front contact a of track relay 2TR, back contact a of relay TESR, and the winding of relay HR to battery terminal N. Relay HR is thus normally in its picked-up position.

Signal lamp G of signal 2G is energized by a circuit which may be traced from battery terminal B, over the front point of contact a of relay HR, and through the filament of the lamp to battery terminal N. Lamp R of signal 2G is energized by a circuit extending from battery terminal B, over the back point of contact a of relay HR and through the filament of the lamp to battery terminal N. Signal 2G thus normally gives a proceed indication and gives a stop indication when relay HR is released by the opening of its pickup circuit. Contacts a and b of circuit controllers CA and CB, respectively, and back contact 0 of relay TESR, assure that relay HR cannot pick up to give a proceed indication following actuations of said controllers and said relay, until these controllers and relays have again returned to their normal positions. This constitutes one of the checking features previously mentioned.

Front contact b of relay 1TR in the pickup circuit for relay TER is employed to assure that signal block 1T is unoccupied before the apparatus arrangement of my invention will operate to clear signal 1G when a train traverses the timing section between controllers CA and CB. The use of this contact is a further checking feature and operates to prevent operation of the apparatus to clear signal 16 when an extra length train traverses signal block 2T.

In FIG. 2 when a train enters signal block 1T, the apparatus operates similar to that described in. the operational example for FIG. 1 except relay TER is released by the opening of front contact b of track relay ITR. However, when the train enters signal block 2T and vacates signal block 1T, front contact b of relay ITR Wrll close to again complete the pickup circuit for relay TER.

When the train enters signal block 2T, the release of track relay 2TR will open, at the front point of contact c of relay 2TR, the previously described pickup circuit or relay ASR. However, relay ASR is maintained in its picked-up position at this time by it previously described stick circuit. The release of track relay 2TR also opens the pickup circuit for relay HR and that relay releases and causes signal 2G to give its stop indication.

When the train enters the timing section beginning at the location of circuit controller or contactor CA, back contact b of controller CA is actuated to its Open position and the stick circuit for relay ASR is thus interrupted. Relay ASR immediately releases, preparing at its back contact b the energizing circuit for relay TESR, and opening at its front contact the pickup circuit for slow release relay TER. As in the operational example given for FIG. 1, if circuit controller CE is actuated to close its contact a before the slow release period of relay TER expires, the previously described pickup circuit for relay TESR is completed and the relay picks up and completes its previously described stick circuit including the back point of contact 0 of relay 2TR. Once picked up relay TESR is thus maintained in that position until signal block 2T is vacated by the train. Signal 16 is controlled to give its proceed indication by the closing of the energizing circuit for lamp G of the signal at the from point of contact 12 of relay TESR, similarly to the manner described in the operational example for FIG. 1. It is to be noted that the immediate release of relay ASR upon the first actuation of controller CA precludes the requirement for controller CA to be a slow-return-to-normal mechanism.

When the train vacates signal block 2T, relay 2TR will pick up, opening the stick circuit for relay TESR and closing the pickup circuit for relay ASR. These relays will accordingly release and pick up, respectively. Relay TER will again become picked up upon the closing of front contact 0 of relay ASR and, providing controllers CA and CB have both returned to their normal unactuated condition, relay HR will pick up to again control signal 2G to give its proceed indication. The picking up of relay ZTR also closes the first energizing circuit for lamp G of signal 1G and that signal will continue to give its proceed indication or, if the speed of the train when traversing the timing section between CA and CB was too slow for relay TESR to become picked up before the release of slow re- =1ease relay TER, signal 1G will be controlled to change its indication from stop to proceed.

It is thus apparent that the apparatus arrangement of FIG. 2 operates in a manner similar to that of FIG. 1 and accomplishes an identical result, that is, the earlier clearing of signal 16 following its control to its stop indication by the passage of a train, providing the speed of the train in signal block 2T is in excess of a predetermined speed. This predetermined speed is based on the period of time required for a train to traverse the timing section between controllers CA and CB, and if the train actuates both controllers within the release period of timing relay TER, the speed of the train is in excess of the predetermined speed.

There is shown in FIG. 3 a stretch of railway track similar to that of FIG. 1 but having no track instrument or contactor CA. Instead of employing contactor CA or similar means at the entering point of the timing section, signal block 2T is provided with an extra track section including a track circuit having a track battery 3TB at one end thereof and a normally energized track relay 3TR located adjacent insulated joints J at the entering end of 6 the timing section. Back contact d of track relay STR is employed in the pickup circuit for relay TESR in place of contact a of circuit controller CA as in FIG. 1. Also back contact e of track relay 3TR is used in the stick circuit for relay TESR in place of back contact 0 of track relay 2TR. A front contact 0 of track relay 3TR replaces back contact b of controller CA in the pickup circuit for relay TER. The signal control circuit for signal 1G includes the front point of contact b of relay 3TR in series with contact b of relay ZTR, and the back point of contact b of relay 3TR in series with contact b of relay TESR. The from point of a contact a of relay STR is included in series with contact a of relay ZTR in the signal control circuit for signal 2G, and the back point of contact a of relay ZTR is included in multiple with the back point of contact a of relay ZTR in that control circuit.

The operation of the appartus arrangement of FIG. 3 is similar to that of FIG. 1, contacts c and d of track relay 3TR performing the same function as contacts a and b of controller CA in FIG. 1, as described below.

In FIG. 3 when a train enters signal block IT and proceeds into signal block ET the apparatus operates similar to that described in the operational example for FIG. 1. When the train enters the timing section beginning at the entrance end of track section ET, the pickup circuit for relay TER is opened at front contact 0 of relay 3TB, and the pickup circuit for relay TESR is prepared at the closed back contact a of relay STR. As in the previous operational examples it circuit controller CB is actuated to close its contact a before the slow release period of relay TER expires, the pickup circuit for relay TESR is completed and that relay picks up and completes its stick circuit including back contact 2 of relay ZTR. Once picked up relay TESR is maintained in that position until signal block ET is vacated by the train. Signal 16 is controlled to give its proceed indication, by relay TESR becoming picked-up and closing the energizing circuit for lamp G of the signal, said circuit including the back point of a contact b of relay ETR and the front point of contact b of relay TESR.

When the train vacates signal block 2T, relay STR will pick up and open the stick circuit for relay TESR which which, therefore, release. Relay TER will again become picked-up upon the closing of front contact 0 of relay 3TR, and the closing of front point of contact a of relay 3TR will again control signal 26 to give its proceed indication through the circuit including front contact a of relay ZTR. The picking up of relay 3TB. also closes an energizing circuit for lamp G of signal 1G, said circuit including in series the front points of contact b of relays ZTR and 3TR, and the front point of contact a of relay LTR. Signal 1G Will continue to give its proceed indication or, if the speed of the train when traversing the timing section was too slow for relay TESR to become picked up before the release of relay TER, signal 1G will be controlled to change its indication from stop to proceed.

From the foregoing description it is apparent that, with the arrangements of apparatus of my invention as shown in FIGS. 1, 2, and 3 of the drawings, new and novel means are provided for permitting a closely following train to at certain times close in on a preceding train, without the sacrifice of the degree of safety usually provided. The arrangements make use of the potential overlap provided by the inertia of the preceding train traveling at a speed equal to or in excess of a predetermined speed.

While I have shown and described only three forms of apparatus embodying my invention, it should be understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination with a stretch of railway track over which trains travel in a predetermined direction, first and second adjacent signal blocks in said stretch; first and second signals at the entrance end of said first and second signal blocks respectively, each signal capable of displaying a stop indication and at least one proceed indication; first and second track occupancy detection means for said first and second blocks respectively for detecting track occupancy of the associated block, circuit means controlled by said first track occupancy detection means for operating said first signal to display its stop or proceed indications accordingly as the first block is occupied or unoccupied by a train, circuit means controlled by said second track occupancy detection means for operating said second signal to display its stop or proceed indications accordingly as the second block is occupied or unoccupied by a train, first means in said second block operable to open a first circuit controlling contact when a train arrives at a first speasso predetermined point in the block, second means in said second block operable to close a second circuit controlling contact when a train arrives at a second predetermined point in the block, a relay, timing means controlled by said contacts for energizing said relay provided the contacts are opened and closed respectively within a predetermined time interval, circuit means controlled by said second track occupancy detection means and said relay for operating said first signal to display its stop indication when the second block is ozcupied by a train and said relay is in its deenergized position, and means controlled by said relay in its energized position for operating said first signal to display its proceed indication when the sccond block is occupied by a train provided said first block is unoccupied by the train.

2. In combination with a stretch of railway track over which trains travel in a predetermined direction, first and second adjacent signal blocks in said stretch, a train governing signal at the entrance end of said first block, track occupancy detection means for each block for detecting track occupancy of the respective block by a train, a first detector at a first point in the second block and operable to open a first contact when a train arrives at that point, a second detector at a second point in the second block a predetermined distance beyond said first point and operable to close a second contact when a train arrives at the second point, a slow release relay, a stick relay, a pickup circuit for said slow release relay including said first contact, a pickup circuit for said stick relay including a front contact of the slow release relay and said second contact, a stick circuit for said stick relay controlled by the track occupancy detection means for the second block in its track occupancy detecting condition for maintaining the stick relay energized when once energized; and circuits controlled by said track occupancy detection means and said stick relay for actuating said signal to display a proceed indication when both detection means detect unoccupied block conditions, and when the detection means for the second block detects a track occupied condition, the detection means for the first block detects a track unoccupied condition, and said stick relay occupies its energized position.

3. In a railway block signaling system for a stretch of railway track in a station platform area, said signaling system comprising, a first signal block in the section of the track stretch adjacent said platform, a second signal block in the section of the track stretch beyond the platform, track occupancy detection means for each said signal block, a signal for governing the entrance of trains into the first signal block, and circuits for controlling the signal to display stop or proceed indications accordingly as said track occupancy detection means detect conditions of track occupancy or unoccupancy; apparatus for permitting a second train to enter the station platform area within a shorter period of time than usual after a first preceding train leaves the station platform providing the speed of the first train after traveling a predetermined distance beyond the platform is greater than a predetermined speed, said apparatus comprising in combination with the foregoing signaling system, a first device at a first point in said second signal block and operable to open a first contact when a train arrives at that point, a second device at a second point in the second block a predetermined distance beyond the first point and operable to close a second contact when a train arrives at the second point, a normally deenergized stick relay, a slow release relay, a pickup circuit for said slow release relay including said first contact closed, a pickup circuit for said stick relay including said second contact closed and a closed front contact of the slow release relay; a stick circuit controlled by the track occupancy detection means for the second block for maintaining said stick relay picked up, when once picked up, so long as that detection means detect a condition of track occupancy; and circuits controlled by said stick relay in its picked up position for controlling iii said signal to display a proceed indication following the vacancy of the first signal block by a train and during the occupation of the second signal block by the train.

4. In a railway block signaling system for a stretch of railway track over which trains travel in a predetermined direction, said signaling system comprising, first and second adjacent signal blocks in said stretch, a signal for governing train movements into the first block, and a track circuit including a normally energized track relay for each block; the combination comprising, first and second detectors at first and second spaced locations respectively in said second block, said first detector operable to open a first contact and said second detector operable to close a second contact when a train arrives at the respective location of each detector, a slow release relay, a stick relay, an energizing circuit for said slow release relay including said first contact, an energizing circuit for said stick relay including said second contact and a front conact of the slow release relay, a stick circuit for the stick relay including a back contact of the track relay for the second block, a first circuit including in series a front contact of each of the track relays for controlling said signal to display a proceed indication; and a second circuit including in series a back contact of the track relay for the second block, a front contact of said stick relay, and said front contact of the track relay for the first block, for controlling said signal to display a proceed indication.

5. In an automatic block signaling system for a stretch of track divided into first and second signal blocks over which trains travel in a predetermined direction each block being provided with a track circuit including a track relay occupying a first position when its rsepective block is unoccupied and including a train governing signal at the entering end of the stretch for said direction of travel operating to give a proceed indication when the track relays occupy their first position to indicate the unoccupied condition of the stretch, the combination comprising, a speed measuring section in said second signal block, a circuit controller at the entrance end of said section operable to open a first contact when a train enters the section, a circuit controller at the exit end of said section operable to close a second contact when the front end of a train leaves the section, a stick relay, means controlled by said contacts for energizing said stick relay when the second contact is closed within a predetermined time after the opening of the first contact during the passage of a train through said section, means controlled by the track relay for the second signal block for maintaining the stick relay energized when once energized and so long as said train occupies the second signal block, and means controlled by said stick relay in its energized position for operating said signal to give its proceed indication when the second signal block only is occupied by the train.

6. In combination with a stretch of railway track over which trains travel in a predetermined direction; first, second, and third adjacent consecutive track sections in said stretch each provided with a track circuit including normally energized first, second, and third track relays rsepectively; a train governing signal at the entrance end of said first section operable to at times give a proceed indication, a circuit controller at a point a predetermined distance within the third track section in said direction of travel operable to close a contact during the passage of a train past said point, a slow release relay, a pickup circuit for said relay including a first front contact of the third track relay, a stick relay, a pickup circuit for said stick relay including in series a first back contact of the third track relay, said contact of the circuit controller and a front contact of the slow release relay, a stick circuit for the stick relay including in series a first one of its own front contacts and a second back contact of the third track relay; a first circuit for controlling said signal to give its proceed indication including in series a second front contact of the third track aces-nae ill relay, a front contact of the second track relay, and a front contact of the first track relay; a second circuit for controlling said signal to give its proceed indication including in series a third back contact of the third track relay, a second front contact of the stick relay, and said front contact of the first track relay; and a third circuit for controlling said signal to give its proceed indication including in series said second front contact of the third track relay, a back contact of the second track relay, said second front contact of the stick relay, and said front contact of the first track relay.

7. In combination with a stretch of railway track over which trains travel in a predetermined direction, a first track section in said stretch provided with a track circuit including a normally energized first track relay, a second track section adjacent said first section in said stretch and provided with a track circuit including a normally energized second track relay, a train governing signal at the entrance end of said first track section operable to at times give a proceed indication, a first circuit controller at a first point in the second track section operable to open a contact only during the passage of a train past that point, a second circuit controller at a second point a predetermined distance beyond the first point in the second track section operable to close a contact only during the passage of a train past the second point, a slow release relay, a pickup circuit for said relay including said contact of the first circuit controller, a stick relay, a pickup circuit for said stick relay including in series said contact of the second circuit controller and a front contact of the slow release relay, a stick circuit for said stick relay including in series one of its own front contacts and a back contact of said second track relay, a first circuit for controlling said signal to give its proceed indication including in series a front contact of each of said track relays; and a second circuit for controlling said signal to give its proceed indication including in series said front contact of the first track relay, a front contact of said stick relay, and a back contact of the second track relay.

8. In combination with a stretch of railway track over which trains travel in a predetermined direction, a first track section in said stretch provided with a track circuit including a normally energized first track relay, a second track section adjacent said first section in said stretch and provided with a track circuit including a normally energized second track relay, a train governing signal at the entrance end of said first track section operable to at times give a proceed indication, a first circuit controller at a first point in said second track section operable to open a contact only during the passage of a train past that point, a second circuit controller at a second point beyond said first point in said second track section operable to close a contact only during the passage of a train past the second point, a first stick relay, a pickup circuit for said relay controlled by a front contact of said second track relay, a stick circuit for said relay controlled by one of its own front contacts in a series circuit with said contact of the first circuit controller, a slow release relay, a pickup circuit for said slow release relay controlled by a first front contact of said first track relay in a series circuit with a front contact of said stick relay, a second stick relay; a pickup circuit for said second stick relay controlled by a back contact of said first stick relay, a front contact of said slow release relay, and said contact of the second circuit controller, all in a series circuit; a stick circuit for said second stick relay controlled by one of its own front contacts in a series circuit with a back contact of said second track relay, a first circuit for controlling said signal to give its proceed indication controlled by a second front contact of the first track relay in a series circuit with a front contact of the second track relay; and a second circuit for controlling said signal to give its proceed indication controlled by a back contact of the second track relay, a

front contact of the second stick relay, and said second front contact of the first track relay, all in a series circuit.

'9. In combination with a stretch of railway track over which trains travel in a predetermined direction, first and second adjacent signal blocks in said stretch, a track circuit for each said block, each circuit including a track relay energized when the respective section is unoccupied, a signal for governing train movements into said first signal block and operable to give a stop indication and a proceed indication, a first track instrument at a first point in said second signal block operable to open a contact when a train arrives at that point, a second track instrument at a second point a predetermined distance beyond said first point in said second signal block operable to close a contact when a train arrives at the second point, a slow release relay, a first stick relay, a second stick relay, a pickup circuit for said slow release relay including in series a first front contact of the track relay for the first signal block and a front contact of said second stick relay, a pickup circuit for said second stick relay including a front contact of the track relay for the second signal block, a stick circuit for said second stick relay including in series one of its own front contacts and said contact of the first track instrument; a pickup circuit for the first stick relay including in series a back contact of the second stick relay, a front contact of the timing relay, and said contact of the second track instrument; a stick circuit for the first stick relay including in series one of its own front contacts and a back contact of the track relay for said second signal block, a first circuit for controlling said signal to give its proceed indication including in series a second front contact of the track relay for the first signal block and a front contact of the track relay for the second signal block; and a second circuit for controlling said signal to give its proceed indication including in series a back contact of the track relay for said second signal block, a front contact of said first stick relay, and said second front contact of the track relay for the first signal block.

10. In a railway block signaling system for a stretch of railway track over which trains travel in a predetermined direction, said signal system comprising, first and second adjacent signal blocks in said stretch for said direction of travel, a signal for governing train movements into the first block, and at least one track circuit for each block each circuit including a track relay; the combination comprising, first detector means at a first point in said second block for detecting the passage of a train at that point and actuated during said passage, second detector means at a second point in the second block a predetermined distance beyond said first point in said predetermined direction for detecting the passage of a train at that point and actuated during said passage, a slow release relay, means controlled by said first detector means for energizing or deenergizing said relay accordingly as said first means is unactuated or actuated following the passage of a train into said second signal block, a stick relay, means controlled by said slow release relay and said second detector means for energizing said stick relay when the slow release relay is energized and said second means is actuated following the passage of a train into said second signal block, first signal control means controlled by said track relays for controlling said signal to give a proceed indication when said track stretch is unoccupied; and second signal control means controlled by said track relays and said stick relay for controlling said signal to give a proceed indication when said first block is unoccupied, said second block is occupied, and said stick relay is energized.

References Cited in the file of this patent UNITED STATES PATENTS 1,278,221 Rowntree Sept. 10, 1918 1,416,622 Dodgson May 16, 1922 1,627,748 Rowntree May 10, 1927 2,088,079 Allen July 27, 1937 

